An investigation into apparent efforts to get contraband into the hands of St. Tammany Parish inmates headed to outside work details led to the arrest of a Covington woman and the termination of a St. Tammany Parish Sheriff’s Office deputy, authorities said Friday.

The probe began three weeks ago when detectives searched a vehicle used to transport prisoners to the detail site and found a bag containing “multiple cellphones and containers of tobacco,” according to the Sheriff’s Office. The items are prohibited in jail or inmates’ work sites.

The car had been assigned to Deputy Tyson Sonnier, who was put on administrative leave.

Detectives conducted dozens of interviews in the course of the investigation but were unable to determine whether the material belonged to Sonnier, according to Suzanne Carboni, a spokeswoman for Sheriff Jack Strain.

In the end, Sonnier was fired because he violated administrative policy by failing to ensure such items didn’t get into the van, she said.

Carboni said deputies do not believe any of the contraband items made it into the jail.

During the course of their investigation, detectives learned of a second scheme, in which a Covington woman was hiding synthetic marijuana in places where the work crew was scheduled to be deployed, according to the Sheriff’s Office.

The woman, Porscha Montana, 26, of the 72400 block of Violet Street, was booked Wednesday with introducing contraband into a penal institution.

Deputies do not believe the two matters are linked, according to Capt. George Bonnett, an office spokesman.